The objective of this proposal is to continue longitudinal, neuro-behavioral follow-up studies of children (N=171) who sustained mild, moderate, and severe closed head injuries (CHI) at 0-15 years of age. These studies, which began in 1984, represent one of only a few prospective follow-up studies in which the child is evaluated at the time of injury and followed at 6, 12, 24, 36, 48, and 60 months post-injury. At this point, follow-up studies have been virtually completed through 24 months. Because of clear evidence for persistent neuro-behavioral sequelae in severely injured children after the first year post-injury, it is proposed to a) obtain 36, 48, and 60 month longitudinal neuro-behavioral follow-up data on CHI children followed since their initial injury and classified according to age and severity; b) expand assessment of behavioral change at 60 months to include additional child, family, and environmental variables, and add additional assessments of academic achievement and problem-solving skills; c) apply multi-level models for growth curve analysis to these longitudinal data. When completed, this study will address hypotheses concerning relationships of pediatric CHI with a) age of onset; b) nature of impaired skill; c) rate of skill development; d) behavioral adjustment and academic skill development. In addition, the application of the growth curve analyses will permit evaluation of medical and demographic factors explanatory of outcomes in individual cases. As such, these techniques promise to revitalize studies of recovery from brain injury by focusing on the analysis of change in individual cases. This study will represent the only long-term prospective outcome data on pediatric CHI, offering new data on neuro-behavioral sequelae after CHI and the development of children who sustain diffuse brain injury at different stages of CNS maturation.